INFECTION CONTROL

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INFECTION CONTROL

• STANDARD PRECAUTIONS
• How to prevent the spread of disease

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Historical Perspective
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• 1847 Dr. Ignaz Philip Semmelweis
• 18 Mortality due to Puerperal Fever caused
  by Streptococcus organism
• First simple case-control study
• Significance of hand washing is demonstrated
• Concept of nosocomial infection is born

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• 1950s Infection Control as an organized and
  recognized discipline is born
• Post World War II hospital-based outbreaks of
  infection caused by Staphylococcus Aureus,
  mostly in newborn nurseries
• Outbreaks demanded an organized response for
  investigation and control

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INFECTIOUS DISEASE PROCESS

• INFECTION presence and multiplication of
  microorganisms in the tissue of the host which
  may or may not have signs or symptoms
• NORMAL FLORA bacteria that are frequently
  found in everyone in specific parts of the
  body
• COLONIZATION presence of bacteria without
  multiplication and damage to the host tissue

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CHAIN OF INFECTION
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The interaction between the 6 elements of the
chain determine whether an infection will result.
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6 Links to the Chain of Infection

• Portal of Entry
• Susceptible Host
• Causative Agent
• Reservoir
• Portal of Exit
• Mode of Transmission

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1 Causative Agent

• Bacteria (includes Richettsia, Chlamydia, and
  Mycoplasm
• Viruses
• Fungi
• Protozoa
• Helminths

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Characteristics of causative agents

• Infective dose
• Pathogenicity
• Virulence
• Invasiveness

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• Characteristics of Causative Agents (Continued.
• Host Specificity
• Viability
• Antigenic Variation
• Resistance

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2 Reservoir

• Humans
• ? Patients
• ? Healthcare Workers

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Reservoirs

• Animals
• Insects
• Rodents
• Shell Fish

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Reservoirs

• Environment
• ? Patient Care Equipment
• ? Environmental Surfaces
• ? Food

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3 Portal of Exit
The path by which the infectious organism (agent)
leaves the reservoir
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• Respiratory Tract
• ? Coughing
• ? Sneezing
• ? Talking
• ? Suctioning

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Genitourinary Tract ? Foley Catheters ?
Sexually transmitted diseases Gastrointestinal
Tract ? Feces ? Vomitus
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Skin/Mucous Membranes ? Wounds ? Skin
breaks Transplacental Blood ? Needle stick ?
Blood Transfusion
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4 Mode of Transmission

• The mechanism for transfer of an infectious agent
  from the reservoir to a susceptible host.

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4 Modes of Transmission

• Contact (Direct and Indirect)
• Airborne
• Vector-Borne
• Common Vehicle

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CONTACT

• DIRECT immediate transmission
• Person-to-person
• Actual physical contact between source and
  patient

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• INDIRECT CONTACT
• Patient to contaminated indirect object
  (contaminated endoscope)
• Droplets spread (large particles that rapidly
  settle out on horizontal surfaces usually
  within 3 feet of source)

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• AIRBORNE
• Organisms contained within droplet nuclei or
  dust particles (i.e. droplet nuclei of
  tuberculosis
• Suspended in air for extended periods, may be
  spread through ventilation systems

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• VECTOR-BORN
• External vector-born transmission mechanical
  transfer of microbes on external appendages
  (feet of flies)

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• Harbored by Vector
• Harbored by vector, but no biological
  interaction between vector and agent (i.e.
  yellow fever virus

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5 PORTAL OF ENTRYThe path by which an
infectious agent enters the suceptible host
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• Respiratory Tract
• Genitourinary Tract
• Gastrointestinal Tract
• Skin/Mucous Membrane
• Trasplacental (fetus from mother)
• Parenteral (percutaneous, via blood

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6 SUSCEPTIBLE HOSTA person or animal lacking
effective resistance to a particular pathogenic
agent
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ISOLATION PRECAUTIONS

• Historical Perspective
• 1877 - Present

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• - First published recommendations
• isolation precautions
• Birth of Infectious Disease Hospitals
• Patients with infectious disease
• process placed in separate facilities
• Aseptic techniques used to combat
• transmission of diseases

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• - isolation practices are altered by
  the introduction of the Cubical system of
  isolation
• Replaced Infectious Disease Hospitals
• Multiple-bed wards
• Barrier Nursing introduced
  

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• Barrier Nursing
• ? Hospital personnel wear gowns between
  patients
• Handwashing between patients with antiseptic
  solutions after patient contact
• ? Disinfection of objects contaminated by
  patents

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1950s - Infection Disease Hospitals begin to
shut down (except for TB sanitariums) 1960s -
TB Hospitals also begin to shut down. 1970 -
Centers for Disease Control publish first manual
on Isolation Techniques for Use in Hospitals
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7 Categories of Isolation

• Strict Isolation
• Respiratory Isolation
• Protective Isolation
• Enteric Isolation

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• Wound and Skin Precautions
• Discharge Precautions
• Blood Precautions
• Disease were lumped into categories based on
  epidemiological features of the disease (resulted
  in under or over isolation)

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1980s - hospitals begin to experience new
endemic and epidemic nosocomial infection
problems caused by multi-drug resistant
organisms 1983 - CDC publishes new Isolation
Guidelines
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• Blood and Body Fluid Precautions
• Strict Isolation
• Contact Isolation
• Respiratory Isolation
• TB Isolation
• Enteric Isolation
• Drainage and Secretion Isolations

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• - Universal Precautions come into being
• HIV
• HBV
• Blood borne pathogens
• 1987 - Body Substance Isolation

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1990s - HICPAC Isolation System Two tiered
system ? Standard Precautions ?
Transmission-based precautions ? Contact ?
Droplet ? Airborne
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NOSOCOMIAL INFECTIONS

• CAUSES AND SITES

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SITES

• Surgical Sites
• Respiratory
• Bone and Joint Infection
• Central Nervous System
• Gastrointestinal System
• Skin and Soft Tissue

• Blood Stream
• Urinary System (UTI)
• Cardiovascular
• Eye/Ear/Throat Mouth Infection
• Reproductive System

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Compromised Patients
Immunocompromised patients vary in their
susceptibility to nosocomial infections,
depending on the severity and duration of
immunosuppression. Use of the two tiered system
essential to break the Chain of Infection.
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3 Major Modes of Transmission in the Healthcare
Setting

• Puncture Wounds
• Skin Contact
• Mucous Membranes (eye/mouth/nose)

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Bloodborne Pathogens

• Hepatitis B Virus
• Hepatitis C Virus
• Human Immunodeficiency Virus

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Role of the Infection Control Nurse/Practioner

• Surveillance
• Track/Trend types of infections
• Education of staff